Spring loaded cover means



April 17, 1962 A. ROBBINS SPRING LOADED COVER MEANS Filed Aug. 24, 1959FIG. 2

FIG.5

INVENTOR ALFRED ROBBINS ATTORNEY Unite States Patent 3,029,972 SPRINGLOADED COVER MEANS Alfred Robbins, Elmhurst, N.Y., assignor toPerfect-Line Manufacturing Corp, Hicksville, N.Y. Filed Aug. 24, 1959,Ser. No. 835,774 1 Claim. (Cl. 220-35) This invention relates to springloaded cover means for outside electrical cover plates, and moreparticularly to such means which have an open position.

Prior cover plates of this type generally used coil type springs so thatthe cover could not be left open unless additional latch or detent meanswere provided. This made these prior plate assemblies difficult toinstall and to use.

The prior coil spring covers were also difiicult to assemble and weresubject to corrosion, especially in outside locations.

The present invention provides a cover plate having a pivotally mountedcover which cooperates with a curved leaf spring, so that when the coveris opened a predetermined small amount, the spring will cause the coverto snap shut. But when the cover is opened more than the predeterminedamount, the spring pressure on the cover will hold the cover in adesired open position. This is accomplished by applying the spring forcethrough one side of the pivot point for small openings and moving it onthe other side of the pivot point for larger openings, as will bediscussed.

Accordingly, the principal object of the invention is to provide new andimproved snap cover means.

Another object of the invention is to provide new and improved snapcover means having an open position, without any additional latchingmeans. 7

Another object of the invention is to provide new and improved snapcover means without the use of coil springs.

Another object of the invention is to provide new and improved snapcover means having a curved leaf spring, bearing against the cover insuch a manner that when the cover is raised a small amount the springwill tend to close the cover; but when the cover is raised more than apredetermined amount, then the spring will hold the cover in the openedposition.

These and other objects of the invention will be apparent in thefollowing specifications and drawings, of which FIGURE 1 is the planview of the embodiment of the invention.

FIGURE 2 is a side view of the embodiment of FIGURE 1.

FIGURE 3 is a detailed view of the curved spring mounting.

FIGURE 4 is a sectional view taken through the lines 44 of FIGURE 1.

FIGURE 5 is a diagram illustrating the operation of the invention.

Referring to the figures, the invention generally comprises a coverplate 1 having a pair of apertures 2 and 3 for the electric plugs to beinserted. A cover 4 is pivotally mounted on a pair of mounting earsconnected to the plate 1 by means of the pin 5. The left-hand side ofFIG- URE 1 shows the construction with the cover plate removed,illustrating the mounting ears 6 and 7, and the curved leaf spring 8which is riveted to the plate 1 by means of the rivet 10.

Referring to FIGURE 3, the curved spring 8 extends slightly beyond theear 6. The spring has a generally U or hook shape, and preferably has abend at one point.

Referring to FIGURE 4, the spring 8 bears against the side 11 of thecover 4 at the point where the rounded side of the cover is tangent tothe spring 8. The portion 4a 3,029,972 Patented Apr. 17, 1962 "ice ofthe cover 4 encloses a hollow space, and the end pieces connected to theportion 4a have suitable mounting holes for receiving the mounting pin5. The spring 8 is preferably of spring steel and is formed and mountedto exert pressure on the cover 4 at all times.

FIGURE 5 shows the operation of the invention. In the closed position ofthe cover 4 a force F is exerted through the bent point S on the springat a distance X from the pivot point. As the cover is rotated opengradually, the spring will be deformed but will not move relative to thecover so that the force P will continue to operate through the point Son the spring and tend to snap the cover shut. However, as the cover isopened still more the limit of motion of the spring will be reached andthe cover will then move relative the spring and the moment arm X willbe gradually decreased until the moment FX is equalled by the frictionbetween the spring and the cover at which balance point the cover willremain open. The cover will also remain open at all greater openingsthan this balance point. This balance point may be adjusted by changingthe shape and/or the strength of the spring.

At large openings of the cover the force F will operate through theother side of the pivot point. When the point B on the cover enters theare of angle A the cover will be fully open substantially perpendicularto the mounting plate 1.

The apparatus is assembled by riveting the springs to v the plate 1 asshown by the rivet 10. The cover is then mounted on the ears 6 and 7 bypassing the pin 5 through the mounting holes 6 and 7' in the ears andcorresponding mounting holes in the portion 4a of the cover 4. The sizeof the spring is chosen and it is positioned to extend out beyond thecurved ends of the mounting cars so that there is spring pressure on thecover at all times.

The apertures 2 and 3 in the plate have a raised lip as at 2a, and thecover preferably has a rubber gasket on its inside which is adapted tomake a good seal against the raised lip of the apertures. The covers areoff-centered with respect to the apertures. The plate 1 is generallymounted with a single screw through the mounting hole 15.

Therefore, the present invention provides new and im proved cover meansfor electrical receptacle plates in which the covers are adapted to bespring loaded shut for small openings of the cover, but which areadapted to be held open at any of a number of different positions by thesame spring. This arrangement permits easy mounting of the plate byinserting a screw through the mounting hole 15, since it may be donewith the covers open. In the prior devices where the covers had a coilspring it was quite awkward to install the plate while holding thecovers open. 1

Many modifications will occur to those desiring to practice theinformation without departing from the scope thereof which is set forthin the attached claim.

I claim:

Spring loaded cover means having adjustable open positions comprising aplate member having an aperture, a generally U shaped curved leaf springconnected at one end thereof to said plate, a shaft mounted on saidplate on the interior side of said U shaped spring, a cover having arelatively flat plate-contacting area pivotally mounted on said shaftand adapted to cover said aperture, said cover having a plane surfacesubstantially perpendicular to the fiat area of said cover adapted tobear tangentially against said U shaped spring, said spring being shapedto apply a force to said cover plane surface on one side of said shaftwhen said cover is in closed position, said spring having a firstarcuate surface located relative said shaft so that as said cover isopened from closed position said spring bends but does not substantiallymove its contact point with and on said cover and tends to close saidcover progressively increase whereby said cover may be held open in aplurality of stable adjustable positions.

References Cited in the file of this patent UNITED STATES PATENTSStorris Dec. 25, '1934 Stieglitz July 20, 1943 Breck Feb. 27, 1951

